Fluid-pressure engine or motor



(No Model.)

-R.A.PARKE. FLUID PRESSURE ENGINE 0R MOTOR.

No. 594,901. Patented De0.7,1897.

To all whom it may concern:

UNITED STATES PATENT FFICE.

ROBERT A. PARKE, OF NEW BRIGHTON, NEW YORK.

FLUID-PRESSURE ENGINE OR MOTOR.

SPECIFICATION forming part of LettersPatent No. 594,901, dated December 1, 1897.

Application filed August '7, 1896.

Be it known that I, ROBERT A. PARKE, a citizen .of. the United States, residing at New Brighton, in the county of Richmond and tate of New York, have invented certain new and useful Improvements in Fluid-Pressure Engines or Motors, of which the following is a specification.

There have heretofore been constructed or proposed various forms of fluid-pressure engines, particularly of the compound type, which may, in stopping, come to rest with the valves and pistons in such relative positions that they may not be readily set in motion again by the mere opening of the throttlevalve or by any ordinary movement of the valve-gear in conjunction with the opening of the same. In all of such. engines it is necessary to provide an additional valve, which is to be operated only for the purpose of starting the engine when the conditions are such that the engine could not otherwise be started in motion. 'lhis starting-valve is usually one of several well-known formsof by-pass valve and will generally be referred toin this specification as the by-pass valve.

It is usual to operate the by-pass valve by,

hand through the instrumentality of mechanism either separate from or the same as that which operates the throttle-valve or the valve gear of the engine. Such by-passvalves are also frequently arranged so that they will be operated automatically at the proper times by means of independent mechanism acted upon by fluid-pressure.

My present invention pertains to engines of the kind referred to, and more particularly to those in which the by-pass valve is operated by the device for controlling the ordinary valve mechanism, but'only by amove .ment of the same beyond the limits necessary for effecting the control of said valve; and it consists in the combination, with the valvecontrolling device, of a by-pass valve operated by a movement of the controlling device beyond the normal limits necessary for the control or operation of the main valves, and an elastic resistance, such as a spring, adapted to be brought under tension by and during such movement and to return the controlling mechanism to its normal limits of operation when the power applied to it for forcing it beyond such limit is relaxed. By this means the operation of the by-pass valve be- Serial No. 601,967. (No model.)

and use my invention, I will now describe 'it' by reference to the accompanying drawing, which forms a part of this specification.

The figure represents in section a fluid-pressure engine to which my improvements are applied.

The engine in the present case is one of the compound trunk type.

A'represents the cylinders, the trunk-pistons within which are shown in dotted lines. B is an inclosed crank-case which, as shown, contains a valve-gear by which the admission of fluid under pressure to the cylinders may be controlled and by means of which also the direction of motion of the engine may be reversed. 4

O is the end view of any suitable device, such as a stem, which projects through the crank-case and which is adapted to be moved by the operator, as by means of the lever D.

(Shown in dotted lines.) One or more arms E, secured to the stem C, are pivoted to a loose collar F on the engine-shaft, which in any lateral movement thereon carries with it Wedges G. (Partly shown in dotted lines.) Supported by the wedges G are'eccentrics H, the positions of which relative to the shaft K depend upon the position of the wedges. The lateral movement of the wedges is necand the cylinders upon opposite sides of the pistons.

Projecting from and secured to the rod or stem C are arms S S, (shown in dotted lines,) which may be brought into contact with pro jecting pins T T (also shown in dotted lines) upon the forked lever U. 1n the position of the stem 0 shown in the drawing the arm S at the" right is in contact with the pin T at 'essarily accompanied by a movement of the loo the right. lVhen the stem C is turned from the position shown through a suflicient angle in a direction contrary to the motion of the hands of a watch, the arm S at the left will similarly come into contact with the pin T at the left side of the forked lever U.

The lever U is secured to the stem V, which is attached to the by-pass valves IV. The by-pass valves are located in a chamber X, which is in open communication with the source of fluid supply. The pressure of the fluid upon the valves V has a tendency to hold them firmly upon their seats. In addition a spring Y is placed upon the stem Vto assist the fluid-pressure in holding the valves upon their seats during all ordinary operations of the engine and to return the forked lever U to its normal position.

The operation of the device is as follows: When it is desired to start the engine in motion, fluid under pressure is admitted by any proper form of throttle-valve to the chamber X, from which it is permitted, by the valves M, to flow through the ports in the bushingR to the cylinders, and there, acting upon the pistons, to start and by means of the proper operation of the pistons and valvegear to keep the engine in motion. By turning the stem 0 into various positions the amount of fluid consumed by the engine, and consequently the amount of power generated can be regulated, and in the same manner the direction of the motion of the crank-shaft is also controlled. The movement of the stem C for the control of the motion of the engine is entirely independent of the movement of the by-pass valves H until toward the limit of the motion of the stem 0 in either direction, when one or the other of the projecting arms S comes into contact with its corresponding pin upon the forked lever U. \Vhen, however, it is desired to start the engineat a time when the valves M are in the positions shown in the drawing, the mere supply of fluid under pressure to the chamberX is not sullicient, because the valves M are in a position to prevent the escape of the fluid from the chamber X through the ports to the passages leading to the cylinders. In this case the stem G is turned to the extreme limit of its motion, whereby one of the projecting arms S engages its pin T and carries the pin along with it through the last fraction of its movement. By this movement the forked lever U is moved slightly in a direction to draw the by-pass valves from their seats, as shown in the drawing. The fluid under pressure in chamber X is thereby permitted to flow past the bypass valves into the passages leading to the cylinders and to thus start the engine in motion. Immediately upon the starting of the engine the operator relaxes his eifort to hold the stem 0 at its extreme position, whereupon the force of the spring V, which is compressed by the movement which raises the valves W from their seats, forces the valves IV to return to their seats and thereby draws the forked lever U back to its normal position.

It will be observed that while in the drawing the by-pass valves are lifted from their seats by contact between the projecting arm S and the pin T of the forked lever 011 the right, if the stem 0 were moved to the limit of its movement in the other direction the arm S and projecting pin T at the left would be engaged with precisely the same effect in lifting the valves W from their seats'.

In the drawing I have shown a special form of reversing and regulating valve-gear; but I do not confine myself to any particular form of engine or valve-gear, as any of the wellknown forms may be made suitable for the purpose. Nor do I confine myself to a lift or puppet by-pass valve, as shown in the drawing, as any other well-known type of valve may be used.

In the construction shown in the drawing the stem 0 is described as having a rocking or rotary motion, which is best adapted to the particular type of valve-gear shown; but as the use of other well-known types of valvegear would make it more desirable that the operating-stem should have an axial instead of a rotary motion the form of the stem or the character of its motion is immaterial so long as it controls the valve-gear. It is adapted to open the by-pass valve when near the limit of its motion.

As the valve-gear illustrated in the draw ing is adapted for reversing the motion of the engine it is necessary to provide for the opening of the by-pass valve toward the extreme limit of movement of the 0perating-stem in both directions. here it is not the purpose to reverse the motion of the engine, it will generally be necessary and desirable to open the by-pass valve or valves toward the extreme limit of the motion of the operatingstem in one direction only.

hat I claim is- In a compound fluid-pressure engine, the combination of high and low pressure cylinders, steam or air chests com mu nicating therewith, piston-valves for distributing the pressure in the said cylinders, an operating device such as a stem for controlling the operation of the distribution-valves, a by-pass valve adapted to admit the fluid under pressure to the cylinders independently of the distribution-valves, the said by-pass valve being connected with the said stem and adapted to be operated by a movement of the same beyond the limits necessary for the operation or control of the distribution-valves, and an elastic resistance, compressed bysuch movement and adapted to restore the stem to normal position when the power necessary for compressing the same is relaxed, as set forth.

G. B. LEWIs, DRURY W. COOPER. 

